Mechanism for pulverizing and feeding fuel.



No. 7411,16?. PATENTBD sEPT.29,19os..

lL. B. NASH n R. 15:. MooRE. MBGHANISM *EUR PULVBRIZING AND FBEDING FUEL.

APPLIOATION FILED KAY 26, 1902.

N0 MODEL.

2 SHEETS-SHEET 1.

ma Nonms Ferias (zo, worum-mn., wnswusmn. n c.

y. PATBNTED SEPT. 29. 1Q-o3. L. B. NASH & R. B. MUGRB. MBGHANISM PORPULVERIZING AND PBBDING FUEL.

APPLICATION FILED MAY 26| 1902.

2 SHEETS-SEEIT 2.

H0 MODEL.

un Hobart E 71200132 lilo. MC-Lidi UNITED STATES atented September 29, 190.

PATENT OFFICE. w

LUGIAN B. NASH AND ROERT E. MOORE, OF CHICAGO, Il`.LNlS.

MECHANISM FOR PULVERIIZING AND FEEDINHFUEL.v

SPECIFICATION forming part of Letters Patent N o. 740,167, dated vSeptember 29, 1903.

Application ne@ nay 25,1902. saturn. 103.902. (ramada.)

To a/ZZ whom, t may concern: Y

Be it known that we, LUGIAN NASH and ROBERT E. MOORE, of Chicago, in the county of Cool; and State of Illinois, have invented certain new and useful Improvements in Me chanisin for Pulverizing and Feeding Fuel and we do hereby declare that the following isv a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specifica. tion.

This invention relates to improvements in mechanism for pulverizing fuel, such as coal, and feeding the pulverized fuel to furnaces; and the invention consists in the matters hereinafter set forth, and more particularly pointed out in the appended claims.

In the drawings, Figure l is a front elevation of aboiler-furnace provided with our improved fuel-feeding devices. Fig. 2 is a transverse vertical section with parts broken away,

showing one set of pulverizing devices and its associated feeding device. Fig. 3 is a partial longitudinal section taken on line 3 3 of Fig. 2. Fig. 4 is a plan section taken on line 4 4 of Fie. 3.

s shown in the drawings, A designates the front wall of the furnace; B, a hopper for the fuel; C, a pipe leading from asource supplying coal and having at its lower end aflaring discharge end C', which lits over the top of the hopper; D D, a plurality of fuel-feeding devices which communicate withV the lower converging side of the hopper and also with' the furnace through the medium of fuel-de livery pipes D'; E, an air-supply pipe communicating with the vfuel-feeding devices Dv through the medium of pipes e; and F,a chainber which contains air or other feeding iiuid under pressure and is connected by a pipe f with the pipe E, said pipe f having a regulating-valve f'. The pipe E may be connected directlyT with an air-pump for affording the desired pressure of the feeding medium or may be connected with a source supplying steam und er pressure if it be desired to use steam as the feeding medium.

The hopper B is made of elongated form and extends practically from one side of the furnace to the other and the feeding devices co n1- inunicate with and receive fuel from the lower converging side of the hopper.

The feeding devices embrace chambered castings D2, the interior chambers .D3 of which receive the pulverized fuel and from whence it is fed to the furnace Y through the fueldelivery pipe D. Said fuel-feeding devices embrace also mechanism for delivering a feeding medium, such as air or steam, to the chamber D8 and pipe D', as Vwill hereinafter more fully appear. Said chambered castings of the feeding devices may be separately connected with the hopper; but I have shown all of said devices embodied in a single casting and provided at its upper side with an elongated haring mouth, which fits within the lower margin of the converging side walls Z9 of the hopper and attached thereto by bolts or like fastening devices. The end walls of said hopper are made somewhat heavier than the side walls and iit at their lower margins against the end walls of the casting containing the feeding devices. The end walls of the hopper will desirably be made of cast-iron plates and the side walls will be made of sheet-metal plates.

Located at the lower end of the hopper and between the same and the feeding-chamber D3 are a plu ral ity of pulverizing devices which receive the fuel from the hopper and crush or pulverize thesame to the desired degree of nenessan ddischarge said pulverizedfuelinto the chainbe r Djof the feeding device,fron1 whence said pulverized fuel is delivered through the pipes D to the furnace. Said pulverizing devices, as herein shown, consist each of two iiatfaeed disks or burs Ff F2,liaving roughened cooperating faces. One of said burs-the bur F2, .as herein shownis rotary and the other is stationary. The rotary burs are aiiixed to horizontal transverse shaft-s F3, which are rotatively mounted 'in bearings in the casting D2 in the 'manner shown in Fig. 4. As therein shown, each shaft is mounted at one end in an integral bearing sleeve or boss cl and at its other side in aY tubular nut d", which is ente-- riorly screw-threaded and engages an inte-v riorly-screW-threaded boss cl2 in a removable" plate cl3, secured at its upper end by bolts clifto C Y the casting D2 and at its lower end by bolts (Z5 to said casing in the region of the fuel-delivery pipe D'. The forward ends of the shafts F3 extend beyond their bearings d and are provided at their outer ends with beveled gear-wheels F4, which mesh with like gearwheels G, which are affixed to a rotary shaft G', mounted in bearings C6, extending outwardly from the hopper, as shown in Fig. l. The gear-wheels G are loosely mounted on the shaft G' and are adapted to be operatively connected with and disconnected from the shaft by means of clutch mechanisms, whereby the operations of the rotary burs may be controlled. Said clutches, as herein shown, consist of spur-clutches l-I of a familar construction and are provided with operatinglevers H', which are pivoted to the adjacent wall of the hopper and to the movable parts of the clutches. Said rotative burs F2 are affixed by the shaft F3 by means of keys or s'plines f2, as shown in Fig. 2, whereby said burs rotate with the shaft, but maybe moved toward or away from the stationary burs in a manner hereinafter to be described. The rotary burs are provided with hubs f3, which engage the inner ends of the adjusting-nuts d', and the keys or splines f2 'of the hubs f3 engage keyways in the shafts, as shown in Fig. 2, said keyways extending to the outer ends of the shafts to permit the burs F2 4to be removed from the shafts. The stationary burs` are provided with hubs F4, having angular exterior surfaces fitting corresponding sockets in projections di, extending inwardly from the casting D2, as shown in Figs. 3 and et, and said hubs are provided with cylindric bores through which the shafts F3 extend and in which said shafts rotate. The stationary burs contact at their central parts with said proj ections (Fand bear near their margins against annular seats or shoulders (Z8, formed on said ,casting LD?, said projections (ZT and annular shoulders D3 constituting a suitable backing to'support the stationary burs duringthe operation of the burs.

The rotary bur of each pair is adjusted with respect to the stationary bur by means of the screw-headed nut (Z, before mentioned, said nut being turned inwardly to move the rotary bur toward the stationary bur and outwardly to permit the rotary bur to be moved away from the stationary bur. lVhen the nut d is moved outwardly away from the stationary bur, the coal entering between the burs presses 'the rotary bur outwardly, with its hub f3 abutting against the inner end of the nut d.

Means are herein shown forsimultaneously moving all of the rotary burs F toward and from the stationary burs for the purpose of varying the iineness of the coal reduced. between the same. Said means consists, as herein shown, of a horizontal shaft I, which is located over said adjusting-nuts d and extends from one end to the other of the device. Said shaft I is provided with screw-threaded sections I', which are adapted to mesh with worin-gears formed on the outer ends of the nuts d in the manner clearly shown in Figs. 2 and 4. Said shaft l is mountedv in bearings t', extending rearwardly from the hopper, and is provided at one end with a handwheel l2, by which the shaft is rotated to turn the nuts d inwardly or outwardly, as desired.

The stationary burs are cut away at their upper parts to provide openings F5, through which the coal passes from the hopper to the spacesbetween the burs. The lower sid e of the hopper is shown as provided with oppositelyinclined parts d5 (Z5, which converge toward the openings F5 of the stationary burs and are arranged to direct the coal from the hopper to said openings, as clearlyshown inFig.

The fuel-delivery pipes D, through which the chambers D3 communicate with the furnace, enter the rear walls of said chambers, and the walls of said chambers are provided in alinement with said pipes D with screwthreaded openings which receive the air-pipes e, which'communicate with the main air-pipe E. The bores of said air-pipes eat their inner ends are screw-threaded and receive short air-tubes J, which extend at their forward ends throughthe chamber D3 and a short distance into the fuel-delivery pipes D'. The outer ends of said air-tubes J are provided around the bores thereof with conical seatsj, and said seats are adapted to be vengaged by conical valves or closures 71:, which are atstems K. Said valve-stems extend outwardly transversely through the pipe E and have screw-threaded engagement with the reduced outer ends of the pipes e, whereby rotary movement of the stems moves the closures toward and from their seats. Said valve-stems extend through stuffing-boxes e' at the outer ends of the air-pipes e and are provided at their outer ends with hand-wheels K,by which said spindles are rotated. The air or other fuel-feeding medium employed passes from the pipe E through the valves,embracing the seats j and closures lo, and thence through the tubes H, and the passage of said. feeding medium into and through the pipes D' creates a vacuum in the chambers D3 and draws the pulverized fuel which drops into said chambers from the spaces between the burs F F2 into and through the pipe D and delivers the pulverized fuel and commingled fuel-feeding medium into the furnace. The supply of air may be accurately regulated with respect to the quantity of pulverized fuel used by means of the air-valves described,orsuch supply of air may be cut off entirely. The supply of fuel delivered to the feeding-chambers D3 from the burs may be also regulated by regulating the speed of the rotary burs.

It may be desirable in someinstances to cut out one set of pulverizing and feeding' devices from the operative series, and this may be accomplished by disengaging through the clutch mechanism described the bur-shafts from the main driving-shaft and by also cutting off the air to the feed-chamber associated therewith through the medium of the airvalve described.

Before stopping the operation of one or Vtached to or-formed on the ends of valvel IUC IIO

more of the burs it is very desirable that all of the fuel fed to the space between the burs be cleared therefrom before operation' of the burs is stopped. For this purpose we have shown a valve or gatelocated between the hopper and the burs so as to cut off the hopper from the burs when one or more of the pairs of burs are to be stopped.

burs is continued until the'burs are cleared. In starting the burs again, rotation of the burs is started before the valves are opened, so that the burs start freely and without exerting an excessive strain on the mechanism,

, tops of the inclined port-ions d at the bottom of the hopper, as clearly shown in Figs. 2 and 3. Said valves are provided with'operatinghandles, which extend outwardly through the hopper. Said valves also serve to regulate the amount of coal to be delivered to the grinders, and by regulation thereof only the amount of coal which it is desired to feed to the furnace need be pulverized. Moreover, by reason of the independent adjustment of the valves certain of the grinders may receive more coal than others, whereby a variable distribution of the coalmay be afforded, as best practice may dictate.

In the mechanism so 'far described it has been assumed that the coal fed to the pulver# izing-burs is of uniform neness and preferably of the size known as pea-coal. We have shown, however, means located in the hopper for reducing larger particles of coal to smaller uniform-sized particles, whereby` the use of the device need not be limited to a certain size of coal. Said means, as herein shown, consists of two parallel horizontal oppositely-rotating rollers M M, located in the hopper above'the valves L and mounted in suitable bearings Ain the end walls of the hopper. Said rollers are provided with radial crushing-arms M', as shown in Figs. 2 and 3, and the arms of one roller pass between the arms of the other roller, whereby coal passed between said rollers is crushed and reduced by said interiitting radial arms. The hopper is provided on the interior walls thereof with inclined ledges BL B4, which act to direct the coal delivered to the hopper centrally over the space between said rollers. Said rollers M are provided at their ends outside of their bearings in the end walls of the hoppers with intermeshing gear-pinions m, wherebyT the rollers are' given positive rotary movement in opposite directions. Said gear-'pinions are rotated through the A medium of a rotative shaft N, which is driven from any suitable source of power and provided with a gearpinion n, which meshes with one of the gearpinions m of the Crusher-rollers. As hereinA shown, the driving-shaft G is also driven from said shaft N, said shaft G being pro- After the vvalve has been closed the operation of the vided with'a gear-wheel G2, which meshes'withr be briefly stated as follows: Coal is fed to the hopper B in quantities'depending upon the demand made thereon by the furnace. If the preliminary crushin g-rollers be employed, said fuel passes between said'crushing-rollers and is by the radial interacting arms thereof reduced to a size by which it may be fed to the spaces between the p ulverizing burs. The coal fed between the pulverizing -burs is pulveriz'ed by the action of said burs and is discharged by the said burs, after being reduced to therequired degree of fineness, into the feed-chambers D3. By reason of the vacuum existing in said chambers, effected by the air-forcing devices before described, the coal dropped into said chambers is caught up by the aircurrents and delivered with considerable force, depending upon the pressure used, into the furnace; It will be observed that the fuel-delivery pipes D' open into the furnace at short distances apart,

Awhereby the fuel is distributed uniformly of the crushing and pulverizing devices, andthe quantity of air delivered by the airforcing devices into the feed-chambers may be regulated to suit the demands brought upon the furnace. As before stated, one or a greater number of the burs and the associated feeding devices may be cut out of the operative series, either for the purpose of regulating the feed or fuel or for the purpose of repairing the burs. When it is desired to remove either of the burs, the removable plate-nut d thereof is removed, after which the plate associated with said nut is detached from the hopper, whereupon said burs are readily accessible for removal.

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An important advantage of the construction Y described is that we are enabled to dispense with the handling of the pulverized fuel,which is necessary in constructions where the pulver ized fuel is fed directly to the hopper and thence tothe feeding devices, thereby obviating the disadvantage of handling the fuel in this state. A further important advantage of the relationv of the pulverizin g-burs tothefeeda state or condition that it may be readily Y handled, (which is not true of the nely-pulverized fuel,) and that the quantity supplied to and pulverized by the grinders or pulverizing device may be regulated in accordance with the demands brought upon the furnace, and of the further fact that .the fuel after it y is pulve-rized has free and unrestricted passage to the furnace, there is no tendency of the fuel to lodge in and choke the feed chambers and passages, such as is likely to occur where a plurality of feed devices are connected with a common source supplying pulverized fuel. In the latter event should one or more of the passages become clogged or partially clogged the varied resistance to the fiow of the fuel through the passages results in a non-uniform feed of the fuel to the furnace, and where an attempt is made to regulatethe flow of fuel by valves the liability of such clogging is increased. The usefulness of an apparatus of the character described depends upon its capability of accurately supplying the pulverized fuel to the furnace in accordance with a desired adjustment, for the reason that the fuel immediately ignites upon its admission to the furnace and irregularities in the supply of the fuel manifests itself at once in a variable temperature of the furnace. This feature of our invention in its application to a multiple pulverizing and feeding device is of great importance, as we are thereby enabled to accurately regulate the amount of fuel fed to the furnace in ac- -cordance with the demands brought upon the furnace, and thereby maintain an even and uniform temperature in the furnace.

The use of the plurality of pulverizing devices operated from a common source of power .by means constructed to separately disconnect each device from said source of power and connected severally by feed-pas sages with the furnace is of great importance, for the reason that when one or more of the grinding and feeding devices is thrown out of action-as for instance, each alternate grinding and feeding device-the power nec-- y range of furnaces.

The provision of the preliminary crushingrollers is of considerable importance, as by the use of the same the apparatus is not limited to fuel reduced to a certain degree of fineness. Vith this construction, therefore, we are' enabled to obviate the inconvenience which would arise in cases where fuel of a certain degree of ineness could not be secured, as byl the construction shown we are enabled to use fuel varying widely in respect to the size of the individual particles thereof.

A further advantage of the construction shown is the extreme simplicity of the mechanism and the employment of few parts. As a result the mechanism is not likely to get easily out of order, thereby rendering the cost of maintenance very economical.

The feeding-chambers D3 are provided in their lower walls with openings closed by screw-threaded plugs, as shown in Figs. 2 and 3,whereby the chambers may be cleaned when necessary.` A further purpose of said openings is to enable the operator to readily ascertain the neness of the fuel being pulverized, it being only necessary to remove one of the pl'ugsto permit a sample of the fuel to drop therefrom. Such sampling of the fuel will usually be done upon starting the mechanism in operation. In this manner the operator or engineer is enabled to at all-times be apprised of the condition of the fuel being consumed.

It is obvious that many changes may be made in the structural details herein shown, so far as the broader aspects of the invention are concerned, and we do not wish to be limited to such details except as hereinafter made the subject of specilic claims.

Ve claim as our invention-i 1. Mechanism for pulverizing and feeding fuel to a furnace comprising, in combination with a furnace, a plurality of pulverizing devices, a source of granular or unpulverized fuel common to and communicating directly with all of said pulverizing devices, a plurality of unrestricted passages leading from said pulverizing devices to different parts of the furnace, and means for separately and forcibly delivering the pulverized fuel from said pulverizing devices through said passages to the furnace.

2. Mechanism for pulverizing and feeding fuel to a furnace comprising, in combination with a furnace, a plurality of pulverizing devices, a source 'of granular or unpulverized fuel common to and communicating directly with all of said pulverizing devices, means for regulating the output of pulverized fuel from the pulverizing devices, a plurality of unrestricted passages leading from said pulverizing devices to different parts of the furnace, and means -for forcibly delivering the pulverized fuel from said pulverizing devices through said passages to the furnace.

3. AMechanism for pulverizing and feeding fuel to a furnace comprising, in combination with a furnace, a plurality of pulverizing devices, a source of granular or unpulverized fuel common to and communicating directly with all of said pulverizing devices, means for separately regulating the output of the pulverized fuel from said pulverizing devices, and means for forcibly delivering the pul- `verized fuel from said pulverizing devices through said passages to the furnace.

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4. Mechanism for pulverizing and feeding fuel to a furnace, comprising, in combination vunrestricted passages leading from said pulverizing devices to different parts of the furnace, means for supplying a feeding medium under pressure to force the pulverized fuel through said passages to the furnace, and

means for varying the force of the feeding medium.

5. Mechanism for pulveriziug and feeding fuel to a furnace, comprising, in combination with a furnace, and a plurality of pulverizing devices, a source of granular or unpulverized fuel common to all and communicating directly with said pulverizing devices, means for regulating the output of the pulverizing devices, a plurality of unrestricted passages leading from said pulverizingvdevices to different parts of the furnace, means for applying a feeding medium under pressure to the several passages to force the pulverized fuel therethrough to the furnace, and means for separately7 varying the supply of the feeding medium.

6. Mechanism for pulverizing and feeding fuel to a furnace, comprising, in combination with a furnace, a hoppen, a plurality of pulverizing devices which receive fuel from said hopper, valves for regulating the supply of fuel 'from said hopper to said pulverizing devices, feeding devices embracing feedingchambers communicating With the furnace through unrestricted passages, each of Which receives fuel from one of the pulverizing devices, and means for supplying a feeding medium under pressure, to said chambers for forcing the pulverized fuel therefrom through said passages into the furnace;

7. Mechanism for pulverizing and feeding fuel to a furnace comprising, in combination with a furnace, a plurality of pulverizing devices operated from a common source Yof power, a source of granular or unpulverized fuel common to and communicating directly with allof said pulverizing devices, a plurality of passages leading from said pulverizing devices to the furnace, means for forcibly delivering the pulverized fuel from said pulverizing devices through said passages Y to the furnace, and means for separately cutting said pulverizing devices out ofthe operative series.

8. Mechanism for pulverizing and feeding fuel to a furnace, comprising, in combination with a furnace, a hopper, a pluralityof pulverizing devices which receive fuel directly from said hopper and are operated from a common source of power, valves between said hopper and the pulverizing devices, means for separately cutting the pulverizing devices out of the operative series, chambers which severally receive the pulverized fuel from said pulverizing devices, passages leading from said chambers to different parts of the furnace, and

means for supplying a feeding medium, under pressure, to force the fuel from the chambers into the furnace. Y

9. Mechanism for pulveriing and feeding fuel to a furnace, comprising, in combination With a furnace, a hopper, a plurality of pulverizing devices which receive fuel from the hopper, shafts for operating said pulverizing devices, gear-Wheels on said shafts, a main driving shaft provided with gear Wheels which mesh with the gear-Wheels of the shafts of the pulverizing devices, means for feeding the pulverized fuel to the furnace and means for separately disconnecting the shafts of the pulverizing devices from the main drivingshaft. r

. l0. Mechanism for pulverizing and feedingfuel to a furnace, comprising, in combination with a furnace, a hopper, a plurality of pulverizing devices receiving fuel directly from said hopper, means for varying the output of the pulverizing devices, a chamber associated with each pulverizing device and receiving the pulverized fuel therefrom, an unrestricted passage leading from one side of each chamber to the furnace, a feeding-medium pipe entering said chamber, in alinement with the fueldelivering pipe thereof, and .means for supplying a feeding medium, under pressure, through said pipe.

In testimony that We claim the foregoing as our invention We affix our signatures, in presence of two Witnesses, this 20th day of May, A. D. 1902. Y

LUGIAN B. NASH. ROBERT E.' MOOR-E.

Vitnesses'.

WILLIAM L. HALL, GERTRUDE BRYCE. 

